package com.test.netty;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.HttpHeaderNames;
import io.netty.handler.codec.http.HttpObject;
import io.netty.handler.codec.http.HttpRequest;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.handler.codec.http.HttpVersion;
import io.netty.util.CharsetUtil;

import java.net.SocketAddress;

/**
 * @ClasName CustomHandler
 * @Descripution TODO
 * @Author USER
 * @Date 2022/3/3 9:55
 * @Version V1.0
 */
// SimpleChannelInboundHandler: 对于请求来讲，其实相当于[入站，入境]
public class CustomHandler extends SimpleChannelInboundHandler<HttpObject> {

    @Override
    protected void channelRead0(ChannelHandlerContext channelHandlerContext, HttpObject httpObject) throws Exception {

        // 获取channel
        Channel channel = channelHandlerContext.channel();

        if(httpObject instanceof HttpRequest){
            //显示客户端的远程地址
            SocketAddress socketAddress = channel.remoteAddress();

            System.out.println(socketAddress);

            // 定义发送的数据消息
            ByteBuf content = Unpooled.copiedBuffer("Hello netty~", CharsetUtil.UTF_8);

            // 构建一个http response
            DefaultFullHttpResponse response = new
                    DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK, content);

            //为响应增加长度
            response.headers().set(HttpHeaderNames.CONTENT_TYPE , "text/plain");
            response.headers().set(HttpHeaderNames.CONTENT_LENGTH , content.readableBytes());

            //把响应刷到客户端
            channelHandlerContext.writeAndFlush(response);
        }

    }

    @Override
    public void channelRegistered(ChannelHandlerContext ctx) throws Exception {
        System.out.println("channel。。。注册");
        super.channelRegistered(ctx);
    }

    @Override
    public void channelUnregistered(ChannelHandlerContext ctx) throws Exception {
        System.out.println("channel。。。移除");
        super.channelUnregistered(ctx);
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        System.out.println("channel。。。活跃");
        super.channelActive(ctx);
    }

    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        System.out.println("channel。。。不活跃");
        super.channelInactive(ctx);
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        System.out.println("channeld读取完毕。。。");
        super.channelReadComplete(ctx);
    }

    @Override
    public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
        System.out.println("用户事件触发。。。");
        super.userEventTriggered(ctx, evt);
    }

    @Override
    public void channelWritabilityChanged(ChannelHandlerContext ctx) throws Exception {
        System.out.println("channel可写更改");
        super.channelWritabilityChanged(ctx);
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        System.out.println("补货到异常");
        super.exceptionCaught(ctx, cause);
    }

    @Override
    public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
        System.out.println("助手类添加");
        super.handlerAdded(ctx);
    }

    @Override
    public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
        System.out.println("助手类移除");
        super.handlerRemoved(ctx);
    }
}
